1. Field of the Invention
The present invention relates to a camera for medical, and particularly dental, use.
2. Description of the Related Art
In the medical domain, and more particularly in the dental domain, micro-cameras are known, whose lens is disposed at the end of a hand piece and which comprise on the body thereof a control knob making it possible to trigger off shot-taking or to capture a specific image.
Such micro-cameras, particularly when they are used in applications where it is necessary to “freeze” an image, are controlled by a specific pedal actuated by the user's foot. In effect, it has been observed that, particularly in this type of applications, the simple actuation of a control knob fast with the camera, however gentle its release, led to generating a movement of the camera having for effect to blur the image which it was desired to “freeze”. Now, this type of pedal-control is used for numerous instruments, particularly in dental surgeries, with the result that it may be awkward for the practitioner to multiply such controls.
Furthermore, different types of release controls which do not require any physical displacement of the user's fingers, are known, such as for example the controls of sensitive type which are constituted in particular by capacitive or inductive sensors which react to the electric field produced by a user's finger.
One of the difficulties encountered in the use of such controls on dental cameras for ensuring “freezing” of an image, is a result of the fact that, contrary to the conventional control knobs which allow a tactile localization, the sensitive controls can themselves only be localized by the practitioner visually, which is not acceptable in the present case insofar as his visual concentration must imperatively be directed on the operative field.
This is why Patent Application FR 02 15014 proposed to provide on the outer face of the body of the camera a zone of surface discontinuity, forming a crest or a hollow, which is disposed plumb with the sensitive sensor, and which allows the user to ensure positioning of his finger with respect to the zone of detection slightly upstream thereof, it being understood that any additional movement of this finger will provoke its detection and consequently the triggering of the appropriate control.
Control systems of sensitive type are usually composed of a sensor (generally a metal pellet) and of electronic means disposed on a support circuit. Now, it has proved that, for various reasons, due in particular to the space requirement, to the global design of the camera, to the aesthetics of the body thereof, or to the presence of various components on the support circuit, it is not possible, in certain configurations, to dispose the sensor and the electronic circuit associated therewith in contact with the inner face of the body of the camera. Now, it is known that, when it is desired that the sensor detects a user's finger precisely and repetitively, it cannot be envisaged to separate the electronic circuit from the sensor in order to position the latter against the inner wall of the body in the immediate proximity of the zone of detection. In effect, it has been observed that the cord link which is in that case established between these two elements has for consequence to destroy the precision and correct repetitivity of the position of detection, insofar as the linking cords become an integral part of the sensor, their position and their length influencing the detection.